1. Field of the Invention
This invention relates generally to biopsy needle devices, and more particularly to a disposable biopsy needle device that includes a safety latch and can be used in either an automatic or semi-automatic firing mode, the biopsy needle device having a dampening system that operates to minimize recoil when the device is fired.
2. Description of Related Art
Various biopsy needle devices are known in the art. A typical biopsy needle device known in the art uses a xe2x80x9cstyletxe2x80x9d in conjunction with a xe2x80x9ccannula,xe2x80x9d both described more fully, to cut a small tissue sample from a precise location within a patient. The stylet and cannula then function to remove the sample from the body for analysis. The typical biopsy needle device of the type comprising (a) an elongate housing, (b) a knob 104 at the first end of the housing, (c) first and second pistons extending from the second end of the housing, (d) connections on the extending ends of the pistons for connecting the stylet and cannula respectively, (e) first and second springs in the housing against which the first and second pistons, respectively, are cocked so that the springs apply a biasing force against the respective pistons, (f) a trigger successive movements wherein the first piston moves force of the first spring while the second piston remains in its cocked position, and after the first piston has moved to its fully extended position, the second piston moves to its fully extended position under the biasing force of the second spring.
A state of the art stylet and cannula is described in Haaga, U.S. Pat. No. 5,718,237. Haaga describes a biopsy needle having coaxial, telescopically inter-engaged stylet, inner and outer cannulas, which are axially and rotatably displaceable relative to one another. The stylet has a distal portion provided with a cutting recess for severing a biopsy specimen from a site in a patient, and the inner cannula has a distal portion for cutting and capturing the specimen in the recess for removal from the site upon withdrawal of the needle from the patient. The distal portion of the inner cannula is partially cut away to provide an insert recess which supports a semi-circular insert of hemostatic collagen which remains at the site upon removal of the needle to minimize hemorrhagic complications by promoting blood clotting. The insert and the distal portion of the inner cannula have radially outer surfaces of corresponding radius whereby the distal portion of the inner cannula and the insert supported therein are received within the distal end of the outer cannula prior to use of the needle.
Bennett, U.S. Pat. No. 5,335,672 describes an improvement in the cocking mechanism wherein the first and second pistons are moved to their cocked positions in separate distinct operations. The improved cocking mechanism comprises an annular ring near the second end of the housing. As the annular ring is rotated, it moves the second piston into its cocked position. The knob on the first end of the housing is pulled in a direction away from the first end of the housing to move the first piston into its cocked position.
Schramm et al. U.S. Pat. No. 5,507,298 describes an apparatus for the automated and facilitated handling and operation of a biopsy needle system, having a first needle component and a second needle component. The first and second needles are provided with first and second handles, respectively, which are fitted into first and second yokes of the apparatus. The apparatus is configured to maintain the first and second needles in a first position, during insertion of the biopsy needle- point into the tissue being sampled. The apparatus is further configured to forwardly move the first and second needles into subsequent positions, respectively, in rapid, automated succession so as to segment and enclose a tissue sample, which may be tested after removal of the biopsy needle system from the tissue. A tissue sample inspection feature permits facilitated repositioning and maintenance of the lo first needle relative to the second needle after retrieval of the tissue sample to enable inspection of the retrieved tissue sample without removal of either needle from the apparatus. The apparatus is further configured so as to be actuatable form position adjacent the front or the rear of the apparatus housing.
Nottke U.S. Pat. No. 4,924,878 describes a spring-powered actuating device for operating the obturator and the cannula of a biopsy needle, and a cocking device removably attachable to the actuating device. The actuating device has a manually operated trigger slide which controls separately the release of spring-powered slides for moving the obturator and the cannula so the surgeon determines the time interval between the release of the obturator and the later release of the cannula. The extent to which the trigger slide can be displaced manually is controlled by a manually adjustable safety slide which may be set in a first position to permit the trigger slide to release the slide for the obturator only and in a second position to permit the trigger slide to release the slide for the cannula. The cocking device, when attached to the actuating device by squeezing them together manually and when so moved it retracts the slides for the obturator and the cannula to stress their springs which power them.
Akerfeldt U.S. Pat. No. 4,953,558 describes an invention referring to a driving unit for advice for tissue sampling. The device comprises in addition to the driving unit a needle unit comprising a hollow outer needle and slidably disposed therein an inner needle, the driving unit being used to propel the needles. The driving unit comprises a driving device for each mechanism adapted to be pretensioned. The driving unit in addition comprises an inner guide sleeve containing two successive needle holders adapted to be shifted in relation to each other in longitudinal direction of the sleeve and adapted to be pre-tensioned in the same direction for propelling the needles with the aid of one spring each and which are provided with releasable locking means. A manual triggering device is provided for releasing the one needle holder who in turn is adapted during the final phase of its propulsion to release the other needle holder. A tensioning sleeve which rotatable surrounds the guide sleeve is provided with cam surfaces cooperating with the needle holders to pre-tension them against he spring force.
Ohto et al., U.S. Pat. No. 5,505,211 describes the set of biopsy needles of the invention is provided with a shaft member for an inner needle which has an inner needle base at the front end to fix an inner needle, a shaft member for an outer needle which has an outer needle base at the front end to fix an outer needle, a gripping member for operation which fixes the shaft member for the inner needle and axially movable support the shaft for the outer needle, a actuating member which gives protrusion force to the shaft member for the outer needle, a holding member which holds the shaft member for the outer needle at the position before protrusion against the protrusion force of the actuating member and releases from holding the shaft member for the outer needle before protrusion by outside operation, and a rotation generating member which gives rotation force to the shaft member for the outer needle when the shaft member for the outer needle moves axially.
Taylor, U.S. Pat. No. 4,907,599 describes the soft tissue core biopsy instrument comprising a proximal outer barrel member and a distal inner barrel member, which is slidably received within the outer barrel member. A cannula driver is slidably received within the distal inner barrel member and has a distally extending cannula fixed thereto. A stylet extends distally from a stylet hub with a stylet hub being removably attached to the proximal outer barrel member. A spring is positioned within the inner barrel member between a proximal wall thereof and a proximal wall of the cannula driver for biasing the cannula driver forwardly and a latching mechanism for latching the cannula driver in a proximally retracted position against the action of spring is also provided. A trigger for unlatching the latching mechanism may be actuated to allow the spring to quickly return to its forwardly biased position, shooting or forcing the cannula driver to a distally extended position, projecting the cannula over the stylet.
Taylor, U.S. Pat. No. 4,881,551 describes the soft tissue core biopsy instrument comprises a proximal outer barrel member having a distal end and a proximal end; a distal inner barrel member which is slidably received within the outer barrel member, which has a distal end and a proximal end and which has a stop in the inner barrel member; a cannula extending distally from the inner barrel member, being fixed to the cannula driver, and having a distal tip, the cannula driver being slidably received in and movable within the inner barrel member and the inner barrel member and the cannula extending a predetermined distance out of a distal end of the inner barrel member when the instrument is in an at-rest condition; a stylet having a distal end, a proximal end, and being removable received in the outer barrel, in the inner barrel, and in the cannula, the distal end having a biopsy sample receiving notch therein; a stylet hub mounted to the proximal end of the stylet; the stylet hub being removably attached to the proximal end of the proximal outer barrel member to enable multiple biopsies to be obtained with one insertion of the cannula, the stylet extending distally from the hub and within the cannula and having a distal tip portion positioned within the cannula when the instrument is in an at-rest position and extending distally of the distal tip of the cannula in position to capture a biopsy sample when the instrument is in a cocked condition; biasing means within the inner barrel member between the stop and the cannula driver for biasing the cannula driver as the inner barrel member for latching the cannula driver in a proximally retracted cocked position within the outer barrel member and the biasing means; and a trigger, associated with the latching means, for unlatching the latching means, the trigger, upon being actuated for unlatching of the latching means, allowing the biasing means to quickly return the cannula driver and the cannula to the distally extending position thereof and over the stylet distal tip portion.
Leigh et al., U.S. Pat. No. 5,172,702 describes a soft tissue biopsy apparatus for obtaining a tissue specimen. An elongate housing has an opening at one end. A hollow cannula is positioned within the housing, is reciprocally movable there within, and one end of the needle extends through the opening for insertion into tissue from which a specimen is to be taken. A needle is positioned within the cannula, reciprocally movable there within, and also has an end extending through the opening for insertion into the tissue. This needle has a recess adjacent its outer end in which a tissue specimen is captured. The needle is connected to a slide by which the needle is moved independently of the cannula. A sleeve installed over the housing is manually operable to move the slide to a selected and cocked position prior to insertion of the cannula/needle into the tissue. Movements of the slide moves the second needle form a first position to a second position while the cannula remains stationary. A release mechanism operable by the user after the insertion of the assembly into the tissue initially returns the needle to its first position and then moves the cannula from a first position to a second position. Movement of the cannula to its second position causes the end of the cannula to cover the end of the needle to capture the tissues specimen within the recess.
The prior art teaches biopsy devices that have the following features: (i) an adjustment mechanism that allows the stroke length of the device to be adjusted, (ii) safety latches to prevent accidental firing, (iii) two overlapping and coaxially aligned coil springs, (iv) a firing mechanism that can be fired in automatic mode or in semi-automatic mode. However, the prior art does not teach a biopsy device that offers all of these features in a single compact housing. The prior art also does not teach a shock dampening device to minimize the recoil of the device when fired. The present invention fulfills these needs and provides further related advantages as described in the following summary.
The present invention teaches certain benefits in construction and use which give rise to the objectives described below.
The present invention provides a biopsy needle device having an axially elongated stylet and a cannula coaxially disposed thereabout, the stylet and cannula being mounted on stylet and cannula bases that are slidably mounted within a cavity of an elongate housing. The cavity also contains a spring-loaded firing mechanism for firing the stylet and cannula for taking a tissue sample from a patient. The stylet base contains a safety stylet latch means and a firing stylet latch means for retaining the stylet in the first, retracted position until released. The cannula base includes a safety cannula latch means and a firing cannula latch means for retaining the cannula base in the first retracted position until released. Once the safety and firing stylet latch means have been released, the stylet base advances to contact a finger of the stop pad, thereby releasing the safety cannula latch lever. The tissue of the patient prolapses into a side-facing notch of the advancing stylet. Once the firing cannula latch lever has been released, the cannula base advances to contact the stop pad, thereby causing the cannula to advance to cover the side-facing notch, thereby severing and containing the tissue. In the preferred embodiment, the stop pad transmits the force of the impact of both the stylet and cannula bases, through a longitudinal adjustment means, to a resilient diaphragm of the housing, thereby dampening the force of the impacts.
A primary objective of the present invention is to provide a biopsy needle device having advantages not taught by the prior art.
Another objective is to provide a single compact biopsy needle device that includes all of the following features: (i) an adjustment mechanism that allows the stroke length of the device to be adjusted, (ii) safety latches to prevent accidental firing, (iii) two overlapping and coaxially aligned coil springs, (iv) a firing mechanism that can be fired in automatic mode or in semi-automatic mode.
A further objective is to provide a biopsy needle device that includes a shock dampening device to minimize the recoil of the device when fired.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.